1. Field of the Invention
The present invention is directed to cryptographic equipment for encoding information to be transmitted, including an encoder stage and a cryptovariable processing stage.
2. Description of the Prior Art
In the transmission of information, particularly voice and data, it is sometimes necessary to ensure that the information to be transmitted is accessible only to authorized personnel. If high secrecy demands are made on the information to be transmitted, it is known, for example, from German OS 21 60 132 to transmit the information in digital form and to encode the information for transmission in a suitable manner with a cryptosignal sequence. At the receiver, the incoming encoded information must then be then decoded with the same cryptosignal sequence in order to regain the original information.
If the secrecy of the information to be transmitted is to be guaranteed, the cryptographic equipment for encoding at the transmission side and for decoding at the reception side must be protected against misuse. It must be ensured that such cryptographic equipment is only accessible to authorized personnel. As soon as the cryptovariable is entered, cryptographic information supplied with such cryptovariables (codes) via a cryptovariable input must be classified for a secrecy level associated with the cryptovariable. When this secrecy level is"Confidential" or higher, the cryptographic equipment must be appropriately secured to prevent access by unauthorized personnel. For example, the equipment may be stored locked in a safe. The use of cryptographic equipment by authorized users is thus made difficult.